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Showy Crotalaria

Showy crotalaria (Crotalaria spectablis)

Francisco Rivera Melendez, UF/IFAS Extension Hillsborough County

Showy crotalaria is a fast-growing summer annual. Like all summer annuals, it germinates in the early spring, flowers in late summer, and set seeds and dies in the fall. Showy crotalaria has simple leaves that are large and waxy. It has yellow flowers that are born on a large, upright stalk. The flowers resemble those of a pea and are quite attractive hence showy being part of the weed’s name. Its other common name, showy rattlebox, comes from its seed pods. The seed pods are short but thick, resembling Vienna sausages, and when dry, rattle profusely when shaken. Showy crotalaria is toxic to all livestock including goats. The seeds contain the highest amount of toxins.

Animals should be prevented from eating the leaves, too, because they contain enough of the alkaloids to be toxic. The leaves of showy crotalaria are toxic even when dried, so producers need to pay extra attention to keep this weed out of hay fields. 

Herbicides:

2,4-D (generic) 2-3 pints per acre
dicamba+2,4-D (generic) 2-3 pints per acre
aminopyralid + 2,4-D (GrazonNext H/L) 1.6 to 2 pints per acre
Triclopyr  (Remedy, Garlon, Element) 2 pints per acre
triclopyr+fluroxypyr (PastureGard) 2 pints per acre